This invention relates to electronic clocks and in particular to electronic clocks having novel display techniques.
There have been disclosed in the prior art electronic clocks using illuminated displays to indicate the time of day by other than an ordinary clock face. In addition to well-known digital readout clocks which display the time of day in arabic numbers, there have been disclosed clocks which display the time of day in terms of binary numbers using lights, such as described by Cuevas in U.S. Pat. No. 3,841,082 and Miller in U.S. Pat. No. 3,750,384. The displays of Cuevas and Miller both use lights to display the time of day in hours, minutes, and in the case of Miller, seconds, in terms of binary numbers. The displays are characterized in that display elements are illuminated to indicate the presence of a binary digit in a number representing the time of day. In both of these prior art clocks, the number of display elements illuminated at any particular time of day is constantly varying from none, or just a few, to substantially all of the display elements.
Kratomi in U.S. Pat. No. 3,744,235 and Fukumoto in U.S. Pat. No. 3,775,964 disclosed clocks in which the time of day is indicated by a display of illuminated elements representing the number of hours and additional displays of illuminated elements representing fractions of an hour. Kratomi's disclosure makes use of portions of a display to represent the number of hours and the number of selected fractions of an hour. His display is similar to that of Cuevas and Miller in the fact that the number of elements illuminated is representative of the time of day. Fukumoto discloses a switching of the illuminated portion of the display to represent the time of day. Thus, Fukumoto's display either utilizes the number of elements illuminated to indicate the number of the hour, or the illumination of a single element to represent a particular hour of the day. One basic disadvantage with most of the prior art devices is that either during a particular time of day, or during the entire day in a system such as described by Fukumoto, only a few elements of the display are illuminated. Since a digital illuminated clock of this type is most attractive when a large number of elements are illuminated, it is desirable to provide a time display which has at all times a large number of display elements illuminated.